engine swap '99 to a 04'?

I want to replace my 1999 GV engine w/ a 2004 engine which has 10 extra hp. Is their any reason/problems the 2004 won't swap? If so what years will?
thanks,
rick502

Yeah, don't do it, all that work and money for 10 hp.

Get a K&N that will give you about 7, and an exhaust at about 6